Gaw object hierarchy


userData
top level window
  globalTable
    toolBar
    ui manager
    hbox for X measure buttons
       measure_button + label
       measure_button + label
       measure_button + label
    scrolled_window  for panel table
      table container for panels
        lmbox container for the left part = (lmhbox | lmvbox)
	lmhbox
	  lmscroll_win
	     lmtable
	       lmtopbox
	       
	       vw_button c0_button c1_button diff_button
	       ... repeated for each visble wave
	       
	  ylabel_box
	     label_layout
	        ylabels
		
	lmvbox
	  logy_hbox
	     ylabel_log
	     ylabel_max
	  lmscroll_win
	     lmtable
	       lmtopbox
	       
	       vw_button c0_button c1_button diff_button
	       ... repeated for each visble wave
	       
	  ylabel_box
	     ylabel_min
	  

        panel  DrawingArea
	
	... repeated for each panel
	
   event_box
     allline_hbox
     	logx_ box
	  logx_label
	  grip_drawing_area
        xlabel_box
	  layout
	    xlabels
   statusbar
   xscrollbar


   DataFile
    WaveTable
    wlist_win list window
      vbox
        wlist_menubar
	label file name
	scrolled_window
	  vbox
	    button wave list button
	    ...




WaveTable : wt
   DataSet
     GPtrArray *datas
       GArray col0
       ...
       GArray coln
     GPtrArray *vars
       WaveVar iv
       WaveVar dv(0)
       ...
       WaveVar dv(n-1)


Growing Politic :
  - the main window size is computed from its components :
     * panels are given the minimal size request 
     * panelTable is given a size request height of n panels user defined
       panelHeight.
     * main scrolled window is given a size request height of n panels user
       defined  panelHeight as long as it stand on the screen.
     * when adding or removing a panel
     * when showing the xlabel box
     * when showing the xmeas_button box  